Remove integration links
Remove integration links

These links are for the old integration hostname and don't fully work on
integration so it seems simpler to remove them and suggest only using
them in a development environment.

This also corrects the development hostname to reference the
govuk-docker one of smart-answers.dev.gov.uk

alphagov/smart-answers,alphagov/smart-answers,alphagov/smart-answers,alphagov/smart-answers